“Since” and “for” are both used to talk about time, especially with the present perfect tense, but they are used in different ways. We use “since” when we talk about a starting point in time It shows when something began. Examples: I have lived here since 2015 She has been sick since Monday We have known each other since childhood We use “for” when we talk about a duration (how long something lasts) Examples: I have lived here for 10 years She has been sick for 3 days We have known each other for a long time Easy way to remember Since = starting point (specific time) For = length of time (how long)